the traffic on free sites converts better than TGP......but you get less traffic to free sites, I would recomend you do both.
Other than Greenie I would highly reccomend the following
richards-realm.com
jays-xxx-links.com
cleos-sex-links.com
dangerdave.com.au
tommys-bookmarks.com
smutgremlins.com
penisbot.com
megapornlinks.com
welovefreeporn.com
hoes.com
markslinks.com
persian-kitty.com
thats a list of some of the big ones, there are loads more.......